CONDUIT (from the French) a canal, or pipe, for the conveyance of water, or other fluid matter ; an aqueduct.
The earth is full of natural conduits, for the passage of waters, which give rise to springs, and of vapours which generate metals and minerals.
Artificial conduits for water are made of lead, cast iron, stone, potters' earth, &c. See PLUMBERY.
Also the reservoir or erection where the waters are con ducted and distributed for use. Previous to the formation of the present water-companies, these conduits were frequent in the diffierent parts of London, and were the only means by which the inhabitants were supplied with water ; the first conduit erected was one near Bow Church, Cheapside, in the reign of Henry Ill. ; and among the latest was one of large dimensions, erected in 1655, at Leadenhall, which served likewise for an ornamental fountain. Conduits of this kind of an early date were usual in our large ecclesiastical estab lishments, and where cloisters existed, there was frequently one in the centre of the quadrangle; which custom has been observed in the quadrangle of S. Augustine's, Canterbury, lately erected, where the conduit, of excellent design, forms an imposing feature.
The first attempt to carry water into the houses of London was made by Peter Morris, A. D. 15S who established the waterworks constructed under two of the arches of old Lon don Bridge, but their supply extended only as for as Grace church-street; soon after, in 1594, similar works were erected near Broken Wharf, which supplied the houses in Westcheap and around S. Paul's, as for as Fleet-street. It was not until the reign of James, that any enterprise of this kind on a large scale was undertaken. when the formation of the New River was commenced by Sir llugh l'sliddleton in 160S, and completed in 1613.
CONE (•om the Greek, Ki,iroc) a solid, bounded by two surfaces, one of which is a circle, called the base, and the other a convexity, ending in a point, called the vertex ; and of such a nature, that a straight line applied to any point in the cir cumference of the base and to the vertex, will coincide with the convex surface.
The straight line drawn from the centre of the base to the vertex of the cone, is called the (i-is.
When the axis of the cone is perpendicular to the base, the cone is called a right cow, but when otherwise, it is called an oblique cone.
It' a cone be cut by a plane through its vertex, the section will be a triangle.
If a cone be cut by a plane parallel to its base, the section will be a circle, or similar to the base.
If a cone be cut by a plane, so as to make the portion cut off to the whole cone, the section will be a circle, or similar to the base.
If a cone be cut by a plane parallel to a plane passing through the vertex, meeting the plane of the base produced without, the section is an ellipsis, except the part cut off be similar to the whole conc, as in the last position.
If a cone, be cut by a plane parallel to a plane in contact with its side, the section will be a parabola.
If a cone be cut by a plane parallel to a section of the cone passing through the vertex, the section will be au hyperbola.
Every cone is one-third part of a cylinder of the same base and altitude (Euclid., b. xii., prop. 10.), and cones of equal altitudes are to each other as their bases (Euclid., b. xii., prop. 11); therefore any cone whatever is the third part of a cylinder of equal base and altitude with the cone.
The curved surface of a cone is equal to the sector of a circle, the radius of which is equal to the slanting side of the cone ; and the are-line of the sector is equal to the circum ference of the base of the cone.
To find the solidity of a cone, multiply the area of the base by the altitude, and one-third of the product will give the solidity. Or, multiply one-third of the area of the base, which is the mean area, by the altitude of the cone, and the product %% ill give the solidity; See CIRCLE.
To find the curved surf•ice of it cone, multiply the slanting side of the cone by the semi-eircumference of the base, and the product will be the area of the curved surfitee.
If the diameter of the base be given, the circumference must be found as directed under the article CIRCLE.
If the perpendicular altitude he given, the slanting side of the cone will be ascertained by the 47th prop., Book i., Euclid. But if the cone be given, it will be much easier to take the slanting side and the circumference of the base, than its alti tude and diameter ; the operation will also be much shorter by taking the former dimensions than the latter. See CONIC